EDUBRIEFS in CCTC

_{Function at the Level of C3}

What Motor Function is Consistent with C3?
The nerve root of C3 runs between vertebrae C3 and C4.  Motor function includes: weak diaphragm usually unable to sustain ventilation weak neck movement (sternocleidomastoid present, weak trapezius)
What Sensory Function is Consistent with C3?
C3 provides sensation for lower neck.
Assessment of C3 Motor Function
Evaluate ability to contract neck muscles (NOTE: cervical spine immobilization limits ability to assess during acute phase). Place examiner's hand over trapezius and ask patient to shrug shoulder.  Assess motor function.  C3 function will provide only weak neck function. Assess ability to turn cheek from side to side (sternocleidomastoid). NOTE: only assess after cervical immobilization has been discontinued.  Muscle strength can be assessed by having patient turn cheek against examiner's resistance.
Assessment of C3 Sensory Function
Test one side, then test same spot on opposite side Always apply the same amount of pressure to each side Ask patient to compare sensation on side A to side B Conceal test from the patient Light touch: use wisp of cotton or tissue; touch neck on either side and assess sensation Sharp or temperature touch: use safety pin, cap of pen or ice cube (do not use needle); assess neck on either side
Expected Outcome
swallowing speaking usually ventilator dependent

Barr, M, and Kiernan, J. (1993). The Human Nervous System: An Anatomical Viewpoint. Philadelphia: Lippincott. pp 84-85.

Keppler, J. (1987). Acute spinal cord injury. Critical Care Clinics. July. 3:3. pp. 638-641.

Netter, F. (1989). Atlas of Human Anatomy. New Jersey: Novartis.

Waxman, S. (1996). Correlative Neuroanatomy. 23rd Ed.  Stamford: Lange. pp 46-52, 352-355, 370.